368 WHALES AND " SEA-SGRPKNTS " CHAp. met with. Most of them are southern in range, and the vast stretches of desolate coast which occur in. these regions of the world account possibly for the rarity of their remains. These Whales have done duty more than once for the ce Sea Serpent/* Quite recently an alleged sea serpent turned out to be a couple of M'esoplodon lying head to tail! The head in these Whales is small compared to the body. The skull is characterised by the strong maxillary crests, enormously deve- loped in the male Hyperoodon. The vertex of the skull too is raised, forming a pronounced prominence behind the aperture of the nares (blow-hole); in many forms the rostrum is made of very dense bone, and is thus relatively abundant in rock strata. The pterygoids meet in the middle line as in the Cachalot. In addition to the few functional teeth in the lower jaw there are more numerous but small teeth in the upper jaw. These are not always to be recognised, as they are not attached to the bone, but merely imbedded in the gums, so that they come away when the skull is prepared. The genus JSerardius * differs from M'esoplodon by its rather more symmetrical skull, of which the vertex is formed by the nasals. The mesethmoid is only partly ossified. The teeth are two on each side of the mandible, with their apices directed forwards. The vertebral formula is C *7, D 10, L, 12, Ca 19. B. arnouxi, from the seas of IN"ew Zealand, is the only species of this genus which is well known. It is 30 or 32 feet in length, and is of a velvety black colour, with a greyish belly. Instead of lowing like a cow, this Whale has been described as " bellowing like a bull" I A singular and somewhat inex- plicable fact has been stated of this species. The teeth were said to be protrusible, and Sir James Hector stated that the teeth were imbedded ** in a tough cartilaginous sac which adheres loosely in the socket of the jaw, and is moved by a series of muscular bundles that elevate or depress it." Sir William Elower justly observed that these statements " accord so little with anything hitherto known in mammalian anatomy that further observations on the subject are extremely desir- able/* Like other Ziphioids, JZerardiits feeds mainly, if not entirely, upon cuttle-fish, a prey eminently suited to their almost toothless mouths. It is not known whether JBeTardius has the 1 See Moww, Trams, jgbol. Soc. viii. 1872, p. 2O3.